Cold Case
by LaraCroftTR65
Summary: A prompt I received from kananovicz. John helps Sherlock to solve one of his cold cases without the pair ever leaving the flat. Includes a bit of a throwback to John as a soldier.


**_A/N I wrote this at the request of my friend, kananovicz. Here is her original prompt for the story. Enjoy._**

I want a scene where Sherlock gives John his cold case trunk, but you'll have to figure out why. And there is a minor case where John knows the victim and he provides Sherlock with some missing details from back then and they solve the case without leaving the flat.

John was sitting at the wooden table in the living room of Baker Street, flicking through his blog, checking for any new case requests. It had been three days and already Sherlock was getting bored. Actually, he was beyond bored. He had already turned the flat upside down in his desperate search for cigarettes, only to find them and claim he didn't want them anymore. John could have killed him. He might have just done it just to stop Sherlock being bored except that it wouldn't be a case for ghost Sherlock because he would already know what had happened. And then ghost Sherlock would have haunted John, complaining about how inefficient his murder had been.

"Don't hide my body there! You're leaving trace evidence."

"Good idea – hide the gun there. _No one _will find it."

"I told you they would find my blood there."

"If you had have followed my advice, you wouldn't be facing twenty years in prison."

No, it was much better to let Sherlock be bored. Or so John though until he heard a thump coming from upstairs.

"Oh Jes-," John groaned, stopping what he was doing to bury his face in one hand.

"Sherlock! What the hell are you doing?" he yelled upstairs.

There was no answer except for a few more loud thuds and the slam of Sherlock's bedroom door. Then he heard the energetic footsteps of his flatmate positively bouncing down the stairs like an overexcited child racing downstairs on Christmas morning to see what Santa had brought.

"It's like living with a five year old," John muttered to himself as Sherlock came whirling into the room in his pyjamas and dressing gown, carrying a worn, old cardboard box with what looked like an acid burn through the bottom left corner. Sherlock floated over to where John was sitting and dumped the box on the table with a huge grin on his face, looking like a puppy that had just brought the stick back to its master. Except John had no idea what Sherlock was giving him or why he looked so happy about it.

"Yeah, that's uh, great, Sherlock, but, eh, what the _hell_ is it?" John asked, pointing to the box questioningly.

Sherlock's smile faded and his brow furrowed as he frowned lightly.

"It's my cold case box."

"Right." John paused. "Why?" he asked, still not able to follow Sherlock's logic of suddenly dredging the box out from wherever it had been stashed in his room.

"Because I solved Carl Powers' case," Sherlock explained. "I have to take it out of here now."

"That was months ago," John pointed out with a puzzled look.

"I've been busy," Sherlock replied defensively, lifting his box and sweeping away gracefully to the sofa, his blue dressing gown swirling out behind him dramatically.

"_He should have been on stage,"_ John thought to himself as he watched the spectacle unfold in front of him.

As Sherlock opened the box, John couldn't help but feel curious. He had never seen Sherlock fail to solve a case before and he wanted to know just what had puzzled the great detective so.

"Can I see?" John asked, gesturing towards the open box. He felt like an idiot at how hopeful he was Sherlock would say yes. He felt like the child now.

Sherlock watched him uncertainly for a few seconds before standing up and carrying the box back to the table where he set it down in front of John. John tried his hardest not to look eager as he pulled the box towards him but he didn't feel he had succeeded as he peered into it.

"Sherlock," he said slowly.

"Hmm?"

"There's only one case left in here."

"Obviously."

"Why do you have a box for one case?"

"There used to be two."

John sighed exasperatedly. "Why do you have a box for two cases?" he corrected himself.

"I don't. Now there's only one."

John groaned and pinched the bridge of his nose.

"For God's sake, why do you have a bloody box for it?"

"They had to be separate from the solved ones," he shrugged as it that explained it all. Well, John supposed it did cover it.

John lifted the remaining cold case out of the box and opened the file. He frowned at the name as a dawn of recognition hit him.

"Wait, Jack Nicholson. He was a soldier, right?" he asked as he flicked through the file.

Sherlock lifted his head and looked at John curiously.

"You knew him?"

"Yeah, sort of," he wrinkled his nose. "But why have you got this case? I thought he was a victim of the war in Afghanistan, killed in an attack by the Taliban. Why have you got it here?"

"Well, that's the story," Sherlock quirked an eyebrow at John.

"But…you don't believe it," John finished, slowly catching on. "Couldn't you prove it though? I mean, there must have been something to make you think that it wasn't the true story."

"I tried, but I couldn't get jurisdiction," Sherlock rolled his eyes and John almost laughed. He could just hear Sherlock's sarcastic comment.

"_Another one of those law things."_

"They wouldn't let you investigate?"

"No and Mycroft said that getting me access to the case was hardly his priority. He said I couldn't go to Afghanistan to investigate anyway, although I'm sure he'd love it really if I walked into the middle of a war zone."

John chuckled amusedly. "Yeah, you're probably right," he joked. He looked back to the file in his hand. "So…what made you think it wasn't an attack?"

"Powder burns," Sherlock replied as if it explained everything. He pulled back the wooden chair from the table and sat down, curling his legs up so that he was sitting cross-legged. He rested his elbows on the table and joined his hands together, placing his fingertips over his lips.

"What about them?" John prompted. He was used to having to pull the story bit by bit from Sherlock. The man was a genius and he forgot that not everyone around him was capable of jumping from one point straight to the conclusion. In Sherlock's head, he could see the logic but he usually left it out of his explanation until John stared at him blankly.

"The powder burns on his head and neck suggest that it was a close range attack," Sherlock expanded.

"And?" John was still waiting patiently for the big reveal.

"And don't you think a close range attack by a terrorist group on a trained soldier seems a little unlikely in this open area?" Sherlock asked, pulling out a picture of a wide open field from the file.

"Jack was found here," he pointed to an area near a thin line of trees which were the only cover that could be seen in the photograph.

"He and one of his fellow soldiers came through those trees moments before he was shot and the survivor, Peter Graham, ran back to base, claiming that they had been attacked and shot at from the trees. The first bullet caught Jack in the back of the head, killing him instantly and Peter dove to the ground, ready to fight back but the attackers must have thought they had caught him too, or maybe had lost the element of surprise and weren't ready for full on warfare, because after a few more shots rang out, the attack ceased. Peter checked Jack but knew he was dead and ran back to base for help."

"Okay, well, things like that could happen in a warzone, Sherlock," John said slowly, studying the photo carefully.

Sherlock raised one eyebrow cynically.

"You're telling me that even one gunman could hide in that narrow expanse of thin trees while two well-trained soldiers plodded through and not get caught, only then to sneak up close enough behind the soldiers to kill one and disappear before his friend, who could have only been metres in front of him, could see and take a shot at him?"

John stared down at the photo in his hands.

"Well, when you put it like that," he trailed off, examining the photo. Now that Sherlock had said it, he supposed it would be rather difficult to hide in that tree line and not get caught. The trees were relatively young and didn't provide a lot of cover. They were sparse and all the leaves and branches were really too small to provide any decent sort of cover, especially if the soldiers had just walked through the area themselves. Surely, they would have noticed someone if they were there.

"But if it wasn't someone in the trees, then who was it?" he asked, looking up to Sherlock who was smirking smugly.

"There's only one person it could have been – only one person who could have been behind Jack and could get close enough without raising his suspicion before shooting him in the back of the head."

Sherlock paused and smiled at John, giving him the '_look'_ – the '_we both know what's really going on here'_ look; the one that pissed John off because he usually didn't know what was going on and it made him feel like an idiot when Sherlock made it out to be so simple.

"And who's that?" he asked with just an edge of annoyance to his voice.

John clenched his jaw angrily as Sherlock gave him a disappointed look.

"Peter."

"Peter?" John chorused, frowning in confusion. "You think Peter shot him?"

Sherlock shrugged.

"It's the only plausible solution."

"But why? What motive did Peter have to shoot one of his own? Why would he kill Jack?"

"That's why I wanted to take the case. Just what exactly pushed Peter Graham to shoot one of his friends in the back of the head?" Sherlock smiled and his eyes sparkled excitedly like this was all one big game for him.

John scratched his head and sighed. "I can't think of anything that would have pushed him to do it. I mean, Jesus, they were on the same side! They were supposed to be fighting together and you think that Peter just led him out into a field and shot him? Why would he do that?"

"Jack's fiancée couldn't seem to think of a reason either," Sherlock said absent minded, staring straight through John, his lips parted a touch as he lost himself in the realms of thought.

"His fiancée?" John repeated in surprise. "I didn't know he was engaged."

"Only recently," Sherlock replied inattentively. "He had asked her just before he went off to Afghanistan."

John hummed thoughtfully in response.

A silence fell over the flat; Sherlock was lost in thought and John was reflecting on the new twist to the story. It was bad enough that the dead man was barely more than a kid but adding a lost love to the story – well, that was just shit.

"And you went to talk to her to see if she had any reason to explain your theory?" John asked after a few moments, shattering the silence into a million little pieces. Sherlock twitched his head jerkily and snapped back into reality.

"Hmm, oh, yes, but Alice couldn't give me anything else apart from the fact that they had all gone to school together and had been best friends. Apparently, the three of them were inseparable," he told him.

"Hang on," John said, sitting up straighter in his chair and leaning an elbow on the table. "Did you say Jack's fiancée was Alice?"

Sherlock's brow furrowed and he watched John carefully. "Yes."

"Because Peter had a tattoo on his back; it was a little heart and in the middle it said 'Ali,'" John remembered, placing a single finger on his lips.

"How do you know that?" Sherlock asked.

"It was one night when the boys all got a little drunk and someone dropped a glass and Peter fell over and it stuck into his stomach. They brought him up to me because I was nearby and they knew I wouldn't say anything about them being drunk," he laughed as he recalled the night four drunken soldiers has stumbled up to his quarters in the middle of the night, barely able to stand or talk.

"I told them to go and clean up the mess before someone found it and reported them while I had a look at Peter. While I was cleaning his cut, I noticed the tattoo and he started telling me how Ali was a really special girl and he loved her and all the other drunken confessions of love."

Sherlock was sitting forward eagerly in his chair now, grinning at John.

"John, you are brilliant!" he crowed. "That's it!"

John chuckled, beaming proudly and shaking his head.

"What's it?"

"That's why Peter shot Jack. The three of them had always been close and Peter had loved Alice, but then she and Jack began dating and Peter began to get bitter. But there was always hope that Alice would leave Jack and come to him instead, so he did nothing about it. But then before they left, Alice secretly agreed to marry Jack and being his best friend, Jack would have told Peter," Sherlock clarified, speaking quickly in his excitement. The words came tumbling out of his mouth like a torrent and he stood up, pacing up and down the living room animatedly.

"Then Peter lost all hope of ever being with Alice and that thought drove him insane. So one day, when everything was quiet, he brought Jack up into the field, and Jack had no reason to be suspicious because he trusted Peter and he didn't know that he was madly infatuated with Alice. Then when they were alone, Peter shot him," he exclaimed, miming the gunshot with his hands.

"Peter then ran back to base, claiming that they had been attacked and there was enough evidence to agree with his story, so case closed. Jack was just another victim of the war."

"Christ, that's cold," John muttered under his breath, staring wide eyed at Sherlock as he rambled on.

Sherlock collapsed onto the sofa with a huge grin splitting his face.

"That's it. Case closed without ever having to go near Afghanistan. I'll have to tell Mycroft to sort it out later," he said, grinning mischievously. He loved causing as much inconveniences for his older brother as possible and he especially loved succeeding in something that his brother had told him not to do.

"And to think he would have gotten away with it if I hadn't seen his tattoo that night," John half-smiled proudly.

"You can leave that one out of the box now as well," Sherlock told him, nodding to the file on the desk. "I think we're done with it."

John left the file on the table and put the lid back on the box.

"That's it," he said with a grin. "Your cold case box is officially empty."


End file.
